Liferay:

Liferay is an open source product for building portals. It is based on JSR 286 released by Sun for portals. If you are not familiar with portals then visit iGoogle . A portal acts as container for other smaller applications called portlets. It has the ability to integrate with already built applications. It is a hot product in the market and a lot of job openings are coming up for liferay. I also written about Liferay interview questions and answers.

We shall cover the following details:

1. Product Overview
2. Liferay features list
3. Liferay Versions
4. JSR 286
5. Core Portlets
6. Conclusion
7. References

Product Overview

Liferay offers various features which improve quality and also reduce time to market. For example, there is inbuilt support for Chat, Message Boards, Calendar, Blog, Wiki, Document Management in Liferay. These features are only a subset of all the features provided by Liferay.

Since Liferay is open source, one can customize various parts of it. These customizations are made easy by the use of hooks, plugins and portlets. The portlets include message boards, polls, wiki, site map and image gallery. Also, one can completely customize the look and feel on the fly.

This tool doesn’t use EJB or JMS and hence can be used with any servlet container like Tomcat. The best part is that it uses latest tools and tech. Some of the Java web technologies used by it are jQuery, Ajax, VAADIN, Spring, Solr etc. Thus it acts as abstraction to these tools and reduces learning curve for developers.

Liferay has a component named Service Builder. It generates the helper code like DAO and DTO to interact with databases. Liferay supports a wide range of databases including HSQL, MySQL, MS SQL, Oracle and DB2 etc. For a complete list of major servers, databases and OS supported by it, see the official page for the same.

Liferay features list

The following is a list of major features:

1) Simplified UI.
2) UI customization for each user.
3) Inbuilt RBAC (Role Based Access) support.
4) Single Sign On.
5) Workflows.
6) Search and Tagging.
7) Localization.
8) Document Management System.
9) Users email notifications.
10) One click LDAP configuration.

Apart from the features listed above, enhancements are done at regular intervals and new version is released. These are based on users feedback and the ideas from developer community. The best part is that there are a number of ways by which one can customize Liferay.

JSR-286

JSR-286 is the Java Portlet specification v2.0 as developed under the JCP and created in alignment with the updated version 2.0 of WSRP. It was developed to improve on the short-comings on version 1.0 of the specification, JSR-168. Some of its major features include:

Inter-Portlet Communication through events and public render parameters
Serving dynamically generated resources directly through portlets
Serving AJAX or JSON data directly through portlets
Introduction of portlet filters and listeners

Source: Java Portlet Specification

Liferay Versions

There are two versions of Liferay available in the market. One is community edition which is free and the other is enterprise edition which has paid support. Since Liferay is so popular, finding solution to common issues is not a problem. There are a lot of forums, websites and blogs with details on any bugs and issues. Liferay EE should be used when professional consulting is required. With Liferay EE, there are two packs viz. Gold and Platinum. They differ in terms of service levels as described officially.

Core portlets

Liferay comes with certain out of the box portlets. These comprise the core functionality of the portal system. They include:

Alerts and Announcements
Alfresco, Documentum, and other document library integration
Asset Publishing
Blogs and blog aggregation
Breadcrumbs
Calendar
Chat
Document and Image management
Document Library Manager, Recent Documents
Image Gallery
Knowledge Base
LDAP Integration
Mail
Message Boards
Nested Portlets
Page Ratings & Flags
Polls
Site Map
Site Navigation
Social Equity
Software Catalog
Tags and Categories
Themes, supporting Velocity and FreeMarker markup
User Directory
Web Content
Web Form Builder
WebDAV Integration
Website Tools
Wiki (supports Creole as well as MediaWiki syntax)

Conclusion

Liferay is used for creating portals and is full of features. It can be used for creating web pages, portals, Blogs full of rich components. Liferay itself uses the portal for its website. There are several benefits of using Liferay which include:

a) Reduced time to market.
b) Low cost of ownership.
c) Rich and intuitive user interface.
d) Reduced learning curve for users and developers.

There two types of editions for Liferay which are Community and Enterprise. The former is LGPL (general public license) and the latter is paid. With Liferay EE, you get official support. Though Liferay is written in Java, it supports plugins which allow PHP and Ruby portlets.

You can see the technical specs for Liferay which are available on their website. All in all, it is user, business and developer friendly and has to offer something for every one. This product has already won many awards and is getting more popular every day.